氟-18-氟代脱氧葡萄糖PET/CT不同时相延迟显像的比较

Comparison of the Different Phase Delayed Scan on ^(18)F-FDG PET/CT

目的:比较研究氟-18-氟代脱氧葡萄糖(18F-FDG)PET/CT不同时相延迟显像对良恶性肿瘤的鉴别诊断价值,确定延迟显像的最佳时间选择。方法:回顾分析80例明确诊断且同时进行18F-FDGPET/CT三时相显像的患者共148个病灶。第1次显像时间为药物注射后64min;第2次(早期延迟显像)时间为110min;第3次(晚期延迟显像)时间为233min。分析每个病灶的最大标准摄取值(SUV),并根据公式滞留指数(RI1)=(SUV2-SUV1)/SUV1×100%;RI2=(SUV3-SUV1)/SUV1×100%进行计算。通过特征工作曲线(ROC)比较分析两次延迟显像的诊断效率。结果:80例患者共148个病灶。109个为恶性病灶,39个为良性病灶。恶性病灶的RI1和RI2分别为(14.8±13.1)%和(10.8±20.5)%;良性病灶的RI1和RI2分别为(11.3±28.2)%和(9.3±42.4)%。RI1的曲线下面积为0.627±0.050(P=0.013),RI2的曲线下面积为0.57±0.06(P<0.05)。早期延迟显像的诊断效率明显高于晚期延迟显像。结论:在应用18F-FDGPET/CT延迟显像进行良恶性鉴别诊断时,采取早期延迟显像可以获得较高的诊断效率。

Objective：To explore the most proper time for delayed scan through the comparison of the early and late delayed scan. Methods： Eighty cases suspected malignancy obtained three phase （64 min, 110 min, 233 min after FDG injection） PET/ CT scan, 109/148 lesions were malignancy, 39/148 lesions were benign, which were proven by pathology, clinical, laboratory and radiological examination. The maximum SUV value in three phase were recorded; Retention index of each lesion in two delayed phase were calculated according to the following formula： RI, and RI2 in both malignant and benign group were analyzed through correlation analysis. The diagnostic value of two delayed image were compared through ROC curve. Results： RI1 ,RI2 in malignancy were 14.8±13.1 %, 10.8 ±20.5%; RI,, RI2 in benign lesions were 11.3 ±28.2 %, 9.3 ±42.4 %. Through analysis of ROC curve, the area under ROC curve for RI1 was 0. 627±0. 050（P = 0. 0130）. The area under ROC curve for RI2 was 0.57±0. 06（P〈0. 05）. The diagnostic value of early delayed image is higher than late delayed image. Conclusion.. Early delayed scan is recommended in clinical practice.